Timeless toxins Researchers have uncovered a rare collection of snake venoms, discovered in boxes in a storage room, some of which are still potent after nearly 80 years in storage.

The collection, containing unique samples from extinct habitats, was analysed by a team of scientists led by Associate Professor Bryan Fry of the University of Queensland.

Reporting in the Journal of Proteomics, Fry expects the collection will shed light on the evolution of venoms, and may even yield compounds that could become drugs.

The boxes belonged to "the Godfather of Australian venom research", Struan Sutherland, who according to Fry, developed the funnel web spider anti-venom. Sutherland, who died in 2002, worked at the Commonwealth Serum Laboratories from 1966 to 1994 and was director of the Australian Venom Research Unit until his retirement in 1999.

Holy grail

When Fry became deputy director of the Unit, he began cataloguing the contents of a store-room.

"Most of it was fairly mundane - and then I opened up these two boxes. It was like Indiana Jones finding the Holy Grail," he says.

Some of the samples have "extreme importance," says Fry. They include the only known venom samples collected from tiger snakes from remote islands in the Bass Strait.

Others are from mainland areas where the snakes' habitats have since been destroyed by clearing and farming.

"And some were from types of death adders that you can't collect any more because they got wiped out by the introduced cane toad," adds Fry.

The venoms, spanning 1935 to 1979, had all either been desiccated or freeze-dried and were kept in the dark, in rubber-stoppered glass tubes. Tests showed that all of the samples, except one, were active, with the venom proteins intact.

"It was incredible that they were still active," remarks Fry.

The rubber stopper of the venom that had deteriorated had corroded and allowed in moisture, said Fry.

"The number one variable is moisture. If you can keep venom dry, you can keep it intact," he says.

Islands of potential

Fry and colleagues sampled tiny amounts of each venom and have carefully stored the remaining portions of the samples for more tests.

"We want to do some basics, you know, find what makes venom protein so stable - just basic biochemistry. Also, we're going to start looking at the perspective of drug design development," he says.

"If you want to find something new and wonderful to use as a drug from a venom, then island snakes are much more likely to yield something, because they've been trapped on an island, following their own evolutionary path."

"Also, from an evolutionary perspective these [island samples] will help us understand how venom evolved."

Snakes of the same species can have quite different venoms if they are in different habitats, says Fry.

In the USA, rattlesnakes of the same species found in mountain and desert regions, only an hour's drive apart, have venoms that target the prey quite differently - one a neurotoxin, the other affecting the blood, he adds.

"A snake venom will typically have at least a hundred different proteins," he says.

One sample in particular gave Fry "goosebumps". It was from the first taipan collected for antivenom. This was collected by 20 year old collector Kevin Budden in 1950, who got bitten in the process.

"Even though he knew he'd been bitten, he made sure the snake was boxed up properly and ready for transport to Melbourne before he went to hospital, where he died the next day."

"There's a deep irony that the snake that ended up saving so many people's lives killed the guy that collected it."

Complex saliva

Commenting on the study, toxicologist Clinical Associate Professor Geoff Duggin, of theUniversity of Sydney, says the circumstances in which the samples were stored were "ideal".

He says therapeutic substances often come from toxicology and agrees that the island snakes may have potential for drug discovery.

"There are a huge variety of substances in venom", he says.

"If you look at them in a comparative sense, the venom glands are like salivary glands and the venoms parallel salivary enzymes. The presumption is that they developed from salivary enzymes."

With so many substances in venom there is scope for considerable differences even among snakes of the same species.

"Those snakes that have the venom that is most effective in a particular [habitat] are the ones that survive," he says.